Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CP3 Medicine > ENDOCRINE - Calcium And Vit D > Flashcards

ENDOCRINE - Calcium And Vit D Flashcards

1
Q

Why is 40% of plasma calcium inactive?

A

Because it is bound to albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

If someone has low albumin, how will their non-adjusted calcium appear?

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Effect on acidotic states on ionized Ca2+ ( why)

A

Increase Ca2+

By decreasing albumin binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Effect on alkalotic states on Ca2+ (ionized) + why

A

Decreased ionized Ca2+

By increasing albumin binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

WHere are the Parathyroid glands

A

Lying posterior to the thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which cells secrete Parathyroid hormone (PTH)

A

Chief cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When is PTH secreted (3)

A

When plasma Ca = low
If Vit D = low
If PO4 = high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

3 ways in which PTH increases plasma Ca levels

A

Directly stimulating Ca reabsorption from bone
Directly increasing renal tubular Ca reabsorption
Indirectly stim incr GI Ca absorption (by incr Vit D activation kidney)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Secondary effect of PTH

A

Increases renal PO4 excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Affect of Vit D on Ca + PO4 levels

A

Sustains/increases both by increasing inflow from GIT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is Vit D synthesised endogenously

A

In kin —> D3 (cholecalciferol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is Vit D ingested exogenously

A

As D2 - ergocalciferol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where does 1st hydroxylation of Vit D take place

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does 2nd hydroxylation of Vit D take place

A

Kidneys = active form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where is calcitonin secreted

A

Parafollicular C cells of thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Calcitonin secreted in response to

A

High levels of Ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does Calcitonin decrease Ca

A

Antagonism of effect of PTH on bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is 90% of renal excretion of Ca related to

A

Sodium reabsorption PCT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the other 10% of Ca renal excretion related to

A

PTH regulation in the distal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

WHat is 97% of hypercalcaemia due to?

A

1’ hyperPTH or malignancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Distinguishing 1’hyperPTH from malignancy

A

PTH high in 1’hyperPTH

PTH low In malignancy + Ca much higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Causes of hypercalcaemia

A

XS PTH secretion - 1/3’hyperPTH + ectopic PTH secretion
Myeloma
Mets deposits in bone
Paraneoplastic - PTHrp (SCC)/Production of osteoclasts factors
XS Vit D - exogenous, TB/Sarcoid/ lymphoma
Milk-alkali syndrome
Thyrotoxicosis
Addisons
Severe AKI
Sx - thiazides diuretics, Li
Familial hypocalcicuric hypercalcaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is 80% of 1’hyperPTH due to

A

Parathyroid adenomas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the other 20% of 1’hyperPTH due to?

A

Diffuse hyperplasia of all glands (e.g. as part of MEN1/2a)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

PTH and Ca2+ levels 1’hyperPTH

A

Ca2+ + PTH high

26
Q

Tx 1’hyperPTH

A

Parathyroidectomy

27
Q

Is parathyroidectomy indicated in asymptomatic 1’hyperPTH

A

YES

Because of potential LT adverse effects

28
Q

After parathyroidectomy, how long does it take for ca2+ to be norm again

A

24hrs

29
Q

Complication parathyroidectomy + how. To prevent it

A

Hypocalcaemia

Give 14 days AdCal post op

30
Q

What is 2’hyperPTH

A

Physiological hypertrophy of all PT glands due to hypocalcaemia

31
Q

Which conditions can cause 2’hyperPTH (2)

A

Renal disease

Vit D deficiency

32
Q

2’hyperPTH - Ca + PTH levels

A

PTH high

Ca low/norm

33
Q

Tx 2’hyperPTH

A

Tx cause

34
Q

What is 3’hyperPTH due to

A

Long standing 2’ hyperPTH esp in renal failure

35
Q

Ca/PO4/PTH levels 3’hyperPTH

A

Ca high
PTH high
PO4 very high q

36
Q

Tx 3’hyperPTH

A

Parathyroidectomy

37
Q

Sx 1’hyperPTH (5)

A 
Usually asymp. 
If Sx: 
BONES
STONES
ABDO GROANS
PSYCHIC MOANS
38
Q

Bone Sx 1’hyperPTH (3)

A

Bone pain
Pathological fractures
Mm weakness

39
Q

Stone Sx 1’hyperPTH

A

Renal stones
Polyuria
AKI/CKD

40
Q

Abdo groans Sx 1’hyperPTH (5)

A 
Abdo pain 
Vomiting 
Constipation 
Pancreatitis 
GI ulcers
41
Q

Psychic moans Sx 1’hyperPTH/hyperCa (4)

A

Depression
Confusion
Tiredness
Hypotonicity

42
Q

ECG changes 1’hyperPTH/hypercalcaemia

A

Reduced QT interval —> cardiac arrest

43
Q

Ix 1’hyperPTH (8)

A 
PTH raised
Ca raised
PO4 reduced
ALP raised 
24 urinary Ca raised 
DXA scan - extent of OP 
Technetium scan - tumour localisation 
USS - tumour localisation
44
Q

Why do we do 24h urinary Ca in Ix 1’hyperPTH

A

To rule out familial hypocalciuric hyerpcalcaemia

45
Q

Classical XR changes 1’hyperPTH

A

Hand XR - classic subperiosteal bone resorption

46
Q

Men 1 - 3 Ps

A

Parathyroid hyperplasia/adenoma
Pancreatic endocrine tumours - gastronomy/insulinoma
Pituitary adenoma

47
Q

Men 2a - TAP

A

Thyroid - medullary carcinoma
Adrenal PCC
Parathyroid hyperplasia

48
Q

Men 2b

A

MEN2+ mucosal neuromas + Marfanoid appearance

No hyperPTH

49
Q

When to Tx hypercalcaemia

A

If >3.5 + severe Sx

50
Q

Tx hypercalcaemia

A

3-6L 0.9% NaCl over 24h

Disphosphonates - 1 dose pamidronate

51
Q

When to use calcitonin in Mx hypercalcaemia

A

Life threatening hypercalcaemia as rapidly reduces Ca

52
Q

When to use dialysis in Mx hypercalcaemia

A

If renal impairment

53
Q

When to use steroids in mx hypercalcaemia

A

If hypercalcaemia = due to myeloma, lymphoma or sarcoid

54
Q

When may hypocalcaemia be an artefact?

A

If low serum albumin is not corrected

55
Q

Causes of hypocalcaemia w/ low PTH (DiGeorge says HIIIII)

A 
Digeorge syndrome 
Severe Hypomagnesia 
Idiopathic (1'hypoPTH)
autoImmune
Iatrogenic - post thyroid/parathyroid surgery 
post neck Irradiation 
Infiltration - sarcoid/malignancy
56
Q

Causes of hypocalcaemia w/ high PTH

A 
Dick and Vagina always relieve Robs anal tension 
Dx - bisphosphonates/calcitonin 
Acute Hyperphosphataemia 
Vit D defcieincy 
Alkalosis 
Renal failure
Rhabdomyolysis 
Acute pancreatitis 
Tumour lysis
57
Q

S+S hypocalcaemia (10)

A 
Peripheral irritability 
Tetany/cramps 
Trosseau's sign 
Chvostek's sign 
Central irritability 
Seizures
Depression/anxiety
Perioral parasethesia 
Cataracts
58
Q

What is Trosseau’s sign

A

Wrist flexion + fingers drawn together
Esp after occlusion of brachial aa ie BP cuff
Hypocalcaemia

59
Q

What is Chvostek’s sign

A

Tapping over facial nn causes twitches

Hypocalcaemia

60
Q

Ix hypocalcaemia (5)

A 
Se Ca = low 
Se PTH = low or high
Check Parathyriod ab if low 
Se Vit D
ECG - prolonged QT
61
Q

Mx mild-mod hypocalcaemia

A

AdCal

62
Q

Mx severe hypocalcaemia (2)

A

Ca gluconate IV 10ml 10% bolus then maintenance infusion

AdCal ASAP

CP3 Medicine (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions